Design Of Fault Location System Of 10 KV Distribution Network Based On Signal Injection Method

The 10 kV distribution network usually adopts neutral point ungrounded or grounded by arc suppression coil.When the ground fault occurs in the distribution line,the fault current is relatively small,and the fault point can not be accurately located.The distribution network include a large number of branch lines,the line fault location is more difficult in the absence of a high degree of power distribution automation.The distribution line is directly related to the reliable use of electricity,so it is of great significance for the rapid and effective fault location of distribution lines.In this paper,the theory and method of fault location for distribution lines are summarized,and the advantages and disadvantages of various positioning methods are compared.In view of the lack of effective fault location device,combined with the method of distribution line fault finding the power supply staff in the practical work,put forward the fault location design of a portable and movable safety measurement in line device.The grounding resistance and the equivalent line distributed capacitance of several kinds of fault grounding modes are studied.The frequency and intensity of low frequency signal are determined,and the FFT algorithm is used to simplify the analysis,calculation and circuit design.The method of threshold analysis is used to judge the fault grounding line,the fast and effective fault location is realized by means of dichotomy.On the basis of the analysis and design of each module of the device,we do a lot of simulation test.The device has good validity and practicability according to test results to optimize the device software detection algorithm and strategy.In this paper,we design a device which can be used in the field of distribution line fault grounding from the portable based on safe and practical point view.It can be used in the production of distribution lines to find a great deal of convenience,can significantly improve the work efficiency to shorten the line outage time,improve power supply reliability and technical level has important practical significance.